Antiaircraft fire control apparatus



Search Hm??? E. VON SEGEBADEN ETAL ANTIAIRCBAFT FIRE CONTROL APPARATUS F eb. 12, 1946.

3 Sheets-Sheet 1' Filed July 3, 1944 ev l, I: l 1 I L? Search Ram 4.23459 'HKUEQ B L510- 66195 Feb. 12, 1946. E. VON SEGEBADEN ET AL 2,394,827

ANTIAIRCRAFT FIRE CONTROL APPARATUS Filed July 3, 1944 3 Sheets-Sheet 2 Feb. 12, 1946- E. VON SEGEBADEN ET AL 2,394,827

ANTIAIRGRAFT FIRE CONTROL APPARATUS Filed July 3, 1944 3 Sheets-Sheet 3 n L1G i-Crl LNG):

Patented Feb. 12, 1946 Search ANTIAIRCRAFT FIRE CONTROL APPARATUS Ernst von Segebaden, Drottningholm, and Ragnar Osterdahl, Stora Essingen, Sweden, assignors to Asenco Aktiebolag. Stockholm,

Sweden, a

Swedish joint-stock company Application July 3, 1944, Serial No. 543,386 In Sweden July 6, 1943 7 Claims.

l -tain constructions and combinations which will be hereinafter fully described and then specifically set forth in the claims hereunto appended.

In the accompanying drawings:

Fig. 1 is a diagram illustrating the theory underlying the invention, with special reference to an arrangement for correction of parallax;

Fig. 2 is a perspective view of an apparatus embodying the invention;

Fig. 3 is a sectional view on the line III--III of Fig. 1;

Fig. 4 is a sectional view on the line IVIV of Fig. 3;

Fig. 5 is a sectional view on the line VV of Fig. 2;

Fig. 6 is a sectional view on an enlarged scale on the line VIVI of Fig. 2;

Fig. '7 is a sectional view on an enlarged scale on the line VII-VII of Fig. 2;

Fig. 8 is a View, partly in section, on the VIII-V'III of Fig. 7; and

Fig. 9 is a diagram illustrating the theory underlying the invention with special reference to the employment of sound locators.

Referring to Fig. 1 of the drawings, the assumption is made that a sighting instrument is positioned at the observing station M at a horizontal distance I) from the battery B for firing at an aerial target F. By means of the sighting instrument an arm I (Fig. 2) is adjusted into an angular position equal to the angle of inclination ,8 of the line of sight MF to the aerial target F. The arm I is secured to a rotatable hollow shaft 2 into which is inserted another rotatable shaft 3 which by means of a bevel gear 4 is connected to a range screw 5 having a slider 6 which is slidably mounted in the arm I. The slider 6 is by means of a pin 1 pivoted to another slider 8 which is displaceable in a vertical guide 9 of a horizontally disposed sliding rod Hi. In the slider 8 is vertically movable still another slider H, to which is secured a pin l2 parallel to the shaft 2. The slider II is mounted on a inserted into a worm wheel I5, which is rotatably journalled on the sliding rod Ill. The spindle I4 is vertically displaceable but not rotatable relative to the worm wheel I5. The worm wheel l5 meshes with a worm I! which is displaceably but not rotatably mounted on a spindle l9 which is provided with a handle Ill. The spindle I9 is rotary journalled in the frame of the apparatus but not displaceable relative same. By turnin the handle the slider H can be displaced vertically in the slider 8, so that the vertical distance between the pins I and I2 will be adjusted.

The pin l2 engages in a longitudinal slot 20 of another arm 2|, which is secured to a hollow shaft 23. The shaft 23 is rotatably journalled on a carriage 22 and a toothed segment 24 is secured to said shaft. The carriage 22 is slidably mounted in a horizontal guide 80, and the centres of the shafts 2 and 23 are positioned in the same horizontal plane. The toothed segment 24 meshes with a pinion 25, which is secured to another pinion 26 that meshes with a toothed rotatable drum 2! rotatably journalled in the frame of the apparatus. The swing of the arm 2| will by this arrangement be transmitted to the drum 21. Into the hollow shaft 23 is inserted a rotatable shaft 28, to which is secured a pinion 29. The pinion 29 meshes with a rack 30, which also meshes with a toothed disc 3| fixed to the pin 12. The shaft 28 is by means of a gear 32 connected to another shaft 33, which by means of a pinion 34 transmits rotary movements of the shaft 28 to a toothed drum 35 rotatably journalled in the frame of the apparatus. Thus the rotary movements of drum 35 indicate variations of the effective length of the arm 21, i. e. the distance between the centres of the pin I2 and the shaft 28. This rotary movement of the drum 35 is not disturbed by the swing of the arm 2| since the pinion 3| does not rotate when the arm 2| is turned.

When the effective length of the arm I, i. e. the distance between the centres of the pin 1 and the shaft 2, by rotating the shaft 3 is adjusted to correspond to the range s of the target F and the arm I by rotating the shaft 2 is ad- J'usted to incline to the horizontal plane at an angle equal to the angle of elevation B the horizontal component MFo=a of the line of sight MF is obtained. This value is by the displacement of the rod I0 transmitted to a mechanism for computing the remaining data of the horizontal triangle MBFo. Said computing mechanism has two arms 36 and 31 connected to oppositely disvertical lead screw [3 the spindle [4 of which is posed hollow shafts 38 and 39, respectively, and

positioned side by side, so that they are free to swing through any desired angles (one complete revolution e. g.). Thus the swing of the arm 36 is unobstructed by the shaft 39, and the swing of the arm 31 is unobstructed by the shaft 38. The axes of the shafts 38 and 39 are located in one and the same horizontal plane, and they are in Fig. 1 represented by M and F0, respectively, so that the distance between them MFo=a. Thus the centres of the shafts 31 and 39 are collonear when the pin 1 occupies a position right above the shaft 2, i. c. When =90. The shaft 39 is parallel to the shaft 38 and rotatably journalled in a downwardly directed bracket 40 of the sliding rod ID. The arms 36 and 31 are pivotally interconnected by a pin 4| the centre of which is in Fig. 1 represented by F0. The direction of the line MFo relative to the direction of origin (the direction of the base line MB) is obtained by rotating a shaft 42 proportionately to the angle a. This angular adjustment is by a gear 43 transmitted to the shaft 38 and further to the arm 36. By rotating another shaft 44 the distance between the centres of the shaft 38 and the pin 4|, i. e. the effective length of the arm 36 is adjusted to indicate the horizontal distance I) (the length of the base line) between the observing station M and the battery B. For that purpose a range screw 35 is rotatably journalled in the arm 36 longitudinally thereof and screwed into a slider 46 carrying the pin 4|. The screw 45 is by a bevel gear 41 connected to a shaft 48 rotary journalled in the hollow shaft 38 and by a gear 64 connected to the shaft 44.

By thus introducing into the triangle computing mechanism the values of a, b and d the horizontal component BFo=a of the range between the target F and the battery B will be ascertained by said mechanism as it is proportional to the distance between the centres of the shaft 39 and the pin 4|. Furthermore, the triangle computing mechanism gives the direction of the line BFo as the adjustment of the angular position of the arm 31 is by the shaft 39, a bevel gear 65 secured to same, another bevel gear 66 secured to a shaft 49 rotatably journalled in the bracket 4|], and a pinion 50 rotatably journalled in the frame of the apparatus transmitted to a toothed drum The angle of inclination of the arm 31 to the horizontal plane is 6 and Adjustments of the distance of the pin 4| from the shaft 39, i. e. the adjustment of the distance a are transmitted to the carriage 22. For that purpose a slider 53 is pivotally mounted on the pin 4| and displaceable in a slot 52 in the arm 31. The slider 53 is rigidly secured to a rack 54 meshing with a pinion 55 secured to a shaft 56, rotatably journalled in the hollow shaft 39. The shaft 56 is connected to a gear wheel 51 which meshes with a rack 58 secured to the carriage 22. Thus the adjustment of the pin 4| longitudinally of the arm 31 will by the rack 54 and other elements be transmitted to the carriage 22. The ratio of dimensions and transmission is chosen so that the pin I2 is positioned right above the shaft 23 if a'=0. If the pins 1 and I2 are positioned at one and the same height above the horizontal plane including the centres of the shafts 2 and 23 the distance between the centres of the pin l2 and the shaft 23, i. e. the effective length of the arm 2| will correspond to the range s between the batter B and the target F. Thus a the horizontal component of s and the altitudinal angle ,6 is the angle of inclination of the arm 2|. The values of 18' and s are transmitted to and by the drums 21 and 35, respectively, As mentioned above the angle 7 has also been ascertained by the triangle computing mechanism and, consequently, the range between the target F and the battery B as well as the direction of the line of sight BF to the target have been ascertained. The values of direction and range are e. g. by electrical means transmitted from the fire control instrument to the battery at B.

The foregoing description was made under the presumption that the sighting instrument at M and the battery at B were on a level with each other. Otherwise, a correction has to be made. If the assumption be made that the battery is positioned at B (Fig. 1), i. e. at a lower level than the instrument at M, the corresponding correction can be introduced into the instrument by downward transversal displacement of the shaft 23, so that the difference of height of the centres of the shafts 2 and 23 corresponds to the vertical distance h. The same result will, however, be obtained in a simplified manner, viz. by displacing the pin I2 upwardly, so that the difference of height of the pins 1 and I2 will be h. Thereby on maintaining a unvariable other values s" and B" of the range and direction will be obtained.

The relative adjustment of heights of the pins 1 and I2 can also for causes of inclined flight be utilized for correction of varying altitude of the target F, if the spindle I9 is controlled by appropriate altitude computing means.

The rack 58 has to transmit from the triangle computing mechanism to the carriage 22 such displacements only relative to the sliding rod III that depend on the longitudinal displacement of said rack, i. e. variations of the distance between the pin 4| and the shaft 39. Hence the swing of the arm 31 must not cause the relative longitudinal movements of the sliding rod I0 and rack 58. Therefore, the gear wheel 51 is not directly connected to the shaft 39 but by means of an epicyclic gear. As shown in Fig. '1, this epicyclic gear has two sun wheels 59 and 60 of equal dimensions and two pairs of planet pinions 6|, 62 of equal dimensions which intermesh by pairs and are rotatably journalled on pins 63 secured to the gear wheel 51. One of the planet pinions 6| of each pair meshes with the sun wheel 59, and the other planet pinion 62 meshes with the sun wheel 60. The sun wheel 59 is secured to the shaft 56, and the sun wheel 60 is idly journalled on the same shaft and rigidly connected to a bevel gear wheel 61 of the same size as the gear wheel 65 and meshing with the bevel gear wheel 66.

Assuming that the shaft 31 is turned without variation of its effective length, i. e. without longitudinal displacement of the rack 54 the shafts 39 and 56 are rotated, and thereby the sun wheel 59 and the gear wheel 65 rotate correspondingly. Thereby the sun wheel 60 is by means of the gear 66, 61 rotated through the same angle but in the opposite direction. Thus the sun wheels 59 and 60 rotate the planet pinions 6| and 62,

respectively, in opposite directions, so that they roll upon each other without rotating the gear wheel 51. If instead thereof the arm 31 does not swing and its effective length a is adjusted the shaft 56 only is rotated. Then the sun Wheel 69 is steady whilst the sun wheel 59 is rotated and drives the planet pinions 6| which in turn 2.6% iitfiilbl UN).

rotate the planet pinions 62. Then the planet pinions 62 roll upon the steady sun wheel 60 and drive the gear wheel 51. Thereby the gear wheel 51 is turned through an angle being the half of the rotary movement of the gear wheel 55. Therefore the diameter of the gear wheel 51 is twice the diameter of the gear Wheel 55, so that a certain displacement of the rack 54 will cause the same displacement of the rack 58,

For the purpose of obviating disturbance of the adjustments of the lead screws 5 and 45 depending on swing of the arms I and 36, respectively, an epicyclic gear similar to that described above is provided between the shaft 3 and the gear 4 and between the shafts 44 and 48.

The apparatus described with reference to Fig. 2 can also be utilized for ascertaining the angle of lead, i. e. point of impact when firing at a movable aerial target or for ascertaining the actual position of such a target at the moment of observation by means of a sound locator. The application of the invention when using a sound locator is illustrated diagrammatically in Fig. 9.

In Fig. 9 the assumption is made that an aircraft flies at a straight course at a constant speed and altitude. The sound locator is positioned at L. If the point A represents the position of the air-craft at the time the sound was emitted, which is heard at L, then the air-craft will be at point by the time the sound reaches the sound locator. The direction of the line L0 is to be ascertained by means of the apparatus as shown in Fig. 2. The range L0 is of no interest in this case. Therefore the distance AL is assumed to be constant, viz. equal to the velocity I c of sound. Consequently, the distance 1 between the points A and 0 represents the speed of the air-craft. The effective length of the arm I of Fig. 2 represents this value. Thus the range screw 5 is adjusted to indicate constant measure of range. The vertical projections of the points A and O on the horizontal plane including the point L are denoted by A and 0', respectively. Thus the triangle LA'O' is horizontal, and the triangles MA and LOO are vertical. AA and 00' represent the constant altitude h. By means of a sound locator the shaft 2 (Figsf2 and 3) is rotated so that the arm I is adjusted into an angle of inclination ;L (Fig. 9) to the horizontal plane. Thereby the length a of the line LA is ascertained and supplied by the sliding rod l0 to the triangle computing mechanism, so that the distance between the centres of the shafts 38 and 39 will be a. By rotating the shaft 42 the arm 36 is adjusted so that its angle of inclination to the horizontal plane including the centres of the shafts 31 and 39 will be r11. The angle t represents the course of the air-craft and is computed by certain means such as that described in the Swedish patent application No. 4681/1943. Furthermore the estimated speed 1 of the air-craft is introduced into the triangle computing mechanism. By rotating the shaft 44 the screw 45 is adjusted so that the effective length of the arm 36 represents the speed 1.

Thereby the data of a, f, and 11/ have been introduced into the triangle computing mechanism, so that also the value of 0 can be obtained, which is represented by the effective length of the arm 31, viz. the distance between the centres of the pin 4| and the shaft '39. Furthermore, the angle is ascertained, which is indicated by the inclination of the arm 31 to the horizontal plane. The angle of inclination p is indicated by the drum 5| as explained in the foregoing. The value '75 of the horizontal component 0 of the range between the air-craft in its actual position at O and the sound locator at L is in the same manner as described in the foregoing transmitted to the carriage 22, so that the horizontal component of the effective length of the arm 2| will be 0. As the altitude of the air-craft is constant the pins I and 23 occupy the same position of height h. The sides h and o of the triangle LOO having been ascertained the angle of elevation e of the line LO will also be ascertained by transmitting the inclination of the arm 2| to the horizontal plane to the drum 21, as described hereinbefore.

If the side LA of the triangle LA'O' is directed at an angle 0) to a line of direction of origin, then the total angl of deflection, i. e. the bearing angle Thus, by means of the apparatus as shown in Fig. 2 the angle of deflection 6 as well as the angle of elevation e of the actual line of sight to the air-craft have been ascertained.

The function of the apparatus as described with reference to Fig. 9 may also be utilized for ascertaining the angle of lead when firing at an air-craft.

In the operation of the apparatus as shown in Fig. 2 it may occur that one or several of the range values represented in Fig. 9 will be equal or approximately equal to zero. Thus if the aerial target is at rest the value 7 is zero, and if said target consists of an air-craft in zenith when emitting a sound and, consequently, the value of a is zero. Furthermore, it might occur that the air-craft is approaching in the azimuthal plane at such a speed that L and O' coincide. In such case the values of ll and o are zero.

The apparatus as shown in Fig, 2 is so constructed that it admits coincidence of the points L and A. In such case the shafts 38 and 39 are collinear. The apparatus admits also the introduction of f=zero. In such case the pin 4| and the shaft 38 are collinear. But if the value of o is at the same time zero the arm 37 is supported at one point only, so that it will obtain an unstable equilibrium, and its direction will be indefinite. Even though the value 0 exceeds zero slightly the effective length of the arm 31 will be too short to enable transmitting with suflicient power of angular adjustments to the arm 2| and drum 21. Therefore, the arm 31 has an abutment 68 adapted to arrest the pin 4| when approaching the shaft 39 and tending to pass a minimum of 0 corresponding to a maximum value of 6. However, if e would exceed this value when the Value of p is zero, then the value of t increases simultaneously. This increasement is directed by the sound locator, which cannot be arrested suddenly. Therefore the arm I is yieldingly connected to the shaft 2, so that the arm I can be arrested when the pin 4| engages the abutment 68 whilst the shaft 2 continues its angular movement corresponding to the increasement of the angle of elevation introduced by the sound locator. As soon as ,0, u or have been changed so that the minimum value of o is again exceeded, the interference of the pin 4| with the abutment 68 is released and the arm I is yieldingly moved into its correct angular position on the shaft 2 on engaging an abutment, as will be described hereinafter.

Interference might also occur by decreasement of a when the arms 36 and 31 are swung into parallel positions, whereat the shaft 39 is positioned between the pin M and the shaft38. Then on decreasement of ,u,i. e.:increasement ofa the abutment 68 approaches thepin .-4I. until interference occurs. Therefore the arm I is yieldingly connected to the shaft 2 also-in an angular direction opposite to that mentioned above. When this interference is finished the correct angular position of the arm I on the shaft 2 is reestablished by a spring which turns the arm into yielding engagement with an abutment, as will be described hereinafter.

The above-mentioned yielding connection of the arm I with the shaft 2 is obtained by means of two tension springs I and II one end of which is connected to a drum I2 fixed to the shaft 2. The other end of each spring I0 and 'II is connected to sliders 1 6 and 11, respectively, which are displaceable each in a circumferential slot I3 and I4, respectively, that extend all around the drum I2 except at a longitudinal interconnection bar I5 serving as a driver and an abutment for the sliders I6 and TI. The arm I is loosely mounted on the shaft 2 and carries a pin I8, which engages in the space between the sliders I6 and 11, when they abut the bar '15.

On interference, viz. arrested swing of the arm I in the direction P, for instance, the rotary movement of the shaft 2 continues in said direction. Then the drum I2 displaces; by means of the bar I5 the slider II in the same direction, whilst the slider 1'6 will still, under the influence of increasing yielding power exerted by the spring Ill, be held in engagement with the pin 18 on the arm I being steady by interference. When the interference is interrupted the arm I is re leased, and thereby the slider 16 engaging the pin I8 will under the influence of the sprin 10 swing the arm I until its pin I engages the slider 'I'I. Thus, in this case the slider 'II serves as an abutment arresting the arm I in a correct angular position relative to the shaft2, viz. the angular position defined by the rotation of the shaft 2 as directed by the sound locator. This spring coupling acts in the same manner, if interference occurs when the shaft 2 is rotated in the opposite direction, viz. the direction P". Thereby the slider 16 will be displaced in that direction, and the slider 11 will on interrupted interference serve as a driver to correct the position of the arm I by moving the pin I8 into engagement with the slider 1'6 now serving as an abutment.

Interference might also occur if the pin 4I hits the abutment because of decreasement of it. Such interference will consequently not be caused by movements of the arm I, wherefore the springs I0 and II acting upon the arm I cannot in this case cause yielding engagement of the pin M with the abutment =68. Therefore yielding engagement is in this case obtained thereby that the shaft 42 is connected to its control handle 80 by means of a spring coupling I9.

Interference might also occur when the speed I of the target is changed if the target moves in the azimuthal plane, viz. when the centres of the pin 4| and the shafts 38 and 39 are located in one and the same'plane and the pin 4I approaches the shaft 39.- Such interference is made yielding by the arrangement of a spring coupling 8I between the shaft 44 and its control handle 82.

We claim:

1. In an apparatus for gun fire controhmeans for trigonometrically computing ballistic values, comprising a triangle computing mechanism having two computing members adapted to represent two sides of. a triangle, a pivot slidably interconnecting said members, and two parallel and transversely displaceable rotatable shafts each of which carries one of said members, the distance between the centres of said shafts, representing the third side of said triangle, said members being interconnected side by side at said pivot, and said shafts projecting from their respective arms in opposite directions, so that each of said members is free to swing unobstructed by the shaft of the other member.

2. In a fire control apparatus for anti-aircraft guns, a vector mechanism having elements adjustable according to the angles of azimuth of two intersecting vertical sight planes, a mechanical vector, means to adjust said mechanical vector angularly according to the angle of elevation of the target in one of said vertical sight planes, means to transmit from said mechanical vector to said vector mechanism a datum of horizontal range of the target, a second mechanical vector pivotally connected to the first mechanical vector and being adjustable angularly according to the target in said other vertical plane of sight.

3. In a fire control apparatus for anti-aircraft guns, a vector mechanism having elements adjustable according to the angles of azimuth of two intersecting vertical sight planes, a mechanical vector, means to adjust said mechanical vector angularly according to the angle of elevation of the target in one of said vertical sight planes, means totransmit from said mechanical vector to said vector mechanism a datum of horizontal range of the target, a second mechanical vector pivotally connected to the first mechanical vector and being adjusted angularly according to the angle of elevation of the target in the other vertical sight plane, and means for transmitting from said vector mechanism to said second mechanical-vector a datum of the horizontal range of the target in said other vertical plane of sight, said vector mechanism comprising two pivotally interconnected range members, one of said range members being connected by an epicyclic gear to said second mechanical vector, whereby said vector is adjustable independently of angular movements of said range member,

4. In a fire control apparatus for anti-aircraft guns, a vector mechanism having elements adjustable according to the angles of azimuth of two intersecting vertical sight planes, a mechanicalvector, means to adjust said mechanical vector angularly according to the angle of elevation of the target in one of said vertical sight planes, means to transmit from said mechanical vector to said vector mechanism a datum of horizontal rangeof the target, a second mechanical vector pivotally connected to the first mechanical vector and being adjustable angularly according to the angle of elevation of the target in the other Luv? having two computing members adapted to represent two sides of a triangle, a pivot slidably interconnecting said members, and two parallel and transversely displaceable rotatable shafts each of which carries one of said members, the distance between the centres of said shafts, representing the third side of said triangle, said members being interconnected side by side at said pivot, and said shafts projecting from their respective arms in opposite directions, so that each of said members is free to swing unobstructed by the shaft of the other member, one of said computing members having an abutment for limiting relative movements of said pivot and the shaft carrying said member.

6. In a fire control apparatus for anti-aircraft guns, a vector mechanism having elements adjustable according to the angles of azimuth of two intersecting vertical sight planes, a mechanical vector, means to adjust said mechanical vector angularly according to the angle of elevation of the target in one of said vertical sight planes, means to transmit from said mechanical vector to said vector mechanism a datum of horizontal range of the target, a second mechanical vector pivotally connected to the first mechanical vector and being adjustable angularly according to the angle of elevation of the target in the other vertical sight plane, means for trans- Search ticciii mitting from said vector mechanism to said secand mechanical vector a datum of the horizontal range of the target in said other vertical plane of sight, one of said elements of said vector mechanism having an abutment for limiting relative movements of said elements, and yielding means for transmitting data to said vector mechanism.

7. In a fire control apparatus for anti-aircraft guns, a vector mechanism having elements adjustable according to the angles of azimuth of two intersecting vertical sight planes, a primary mechanical vector adjustable angularly according to the angle of elevation of the target in one of said vertical sight planes, means to transmit from said mechanical vector to said vector mechanism a datum of horizontal range of the target, a secondary mechanical vector pivotally connected to said primary mechanical vector and being adjustable angularly according to the angle of elevation of the target in the other vertical sight plane, means for transmitting from said vector mechanism to said secondary mechanical vector a datum of the horizontal range of the target in said other vertical plane of sight, and yielding driving means for said angular adjustment of said primary mechanical vector.

ERNST vo-N SEGEBADEN.

RAGNAR STERDAHL.

Certificate of Correction Patent No. 2,394,827. February 12, 1946. ERNST VON SEGEBADEN ET AL.

It is certified that the name of the assignee in the above numbered patent was erroneously described and specified as Aseneo Aktiebolag" whereas said name she have been described and specified as Arenco Akh'ebolag; and that the said Letters Patent should be-read with this eorrection therein that the same may conform to the record of the ease in the Patent Oflice.

Signed and sealed this 28th day of May, A. D. 1946.

LESLIE FRAZER,

First Assistant Commissioner of Patents. 

